Thread severing and holding mechanism for sewing-machines.



J. W. DARLEY, JR.

THREAD SEVERING AND HOLDING MECHANISM FOR SEWNNG MACHINES.

APPLlCATlON FILED JULY 7. 1910.

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AND I l (91f:EEK 1M3v MECHANISIVIEOR SEWING-MACHINES.

Patented May 25, ltlilti'.

epplicetion filed/April. 6, 1910, ticriel lilo. 553,772. Bividcd andthis application filed July 7, 1910.

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T all wiiomqitmag concern Be it known that l, J OHN W. Deanna", .911,

a citizen oi the United States, residing at Baltimore, in the State ofMaryland, have invented certain new and useful Improvements in ThreadSevering and Holding Mechanism for Sewingl/lsohines; and 1 do declarethe following to be e full, clear, end exact description oi theinvention, such wille'nable others skilled in the art to which-it eppertcins to make and use the some. i

My invention relates to improvements in thread severing and holdingmechanism for sewing machines, and is especisll vdesigned for sewingmachines used for attaching buttons to garments, but it is notrestricted to his special class of sewing machines, as it is capable ofgeneral application.

This application is a division of my former application No.553,772,1iled April is an inverted plan view of the severing'inechanism, showing trimmers for the needle and shuttle threads and theholding dcvices for the needle thread, in the position of rest. Fig. '2is a similar view, the operating part being omitted, and showing theports in the position at the end of the first stitch. Fig. 8 is a,similar view, showing the parts in the position at the end of. thefourth stitch. Fig. 41 is a perspective view, on a larger scale, of thetrimmers and one of the holding means for the needle thread. 5 is sperspectiveview of the other member of the holding device for the needlethread. Fig. 6 is a, cross-section on the line 6-6 of Fig. 4:.

The shuttle is supported below the bed plate in the usual manner andoperates in the usual way. The additional new features neculiar to thisinvention are shown most clearly in Figs, e and 5.

26 end 27 are knives. of well, known construction, for severing theshuttle thread and needle thread, respectively, and the holder 28 is ofwell known construction also, and is adapted to hold the beginning endof the needle thread. The knives and driving gear 29 are all mounted ona pivotpin 30, and below the knife 27 is a curved guard 31, attached tothe operating gear by the same screw 32 that holds the knives 26 and 27thereon, and it is kept in position by the pin 33', which also preventsthe thread holder 28 from being displaced.

Attached to the throat plate 35 which forms a part of the body of themachine, by means of screws is a curvedjarm 36, which terminates at itsfree end in a flat portion 37, provided with lip-turned ends 38, whichpart 37 is adapted to lie in the path of the thread holder 28. The armEd is of spring metal, holding; the end 37 against the throat plate.unless is displaced by the thread holder 28. 1

40 represents the free end of the needle thread and 41 a hole in thethroat plate, through which this needle misses.

The operation is as iollows:llhe machine is threaded and the buttonsewed on as described in my said companion applications, and need not bespecifically described here. A loop is formed in the needle thread andthe point of the shuttle hook enters this loop in the well known manner,and the further movement of the shuttle polls down the free end 40 ofthe needle thread through the hole 4 in the throat piste. During thisdownward movement, the needle thread is clamped in the well knownmanner, so that the thread cannot be pulled through the hole in the endof the needle toward the shuttle, thus causing the shuttle to pull theend 420 of the needle thread through the hole ll. The needle thencontinues to rise, and at a point near the end of the upward motion ofthe needle during the first stitch, the entire system of parts shown inFig. moves, bringing, the hook; on the thread holder 28 across the holell in the throat plate, pulling the end 40 of the needle. thread alongwith it, and binding it between itself, the throst piste. end theportion 87 of the spring arm 36. The sewing then continues and duringthe second stitch, and. at about the time when the'shuttlc hook engagesthe loop in the needie thread, this thread is unclemped, so that "theneed thread is drawn under the flat tened portion 37 of the spring arm36, which springs up and clamps the end between itself and the throatplate as the hook on the thread holder 28 releases the thread. It isevident that it the end of the needle thread were not confined in someway after it is released by the thread holder 28, it would be caught bythe loops of the needle thread during successive stitches, making anunsightly appearance on the under side of the fabric, which is avoidedby the construction shown.

The parts remain in the position shown in Fig. 3, until the beginning ofthe tourteenth stitch (the machine being arranged to make that number ofstitchesin sewing on a button, although any number of stitches mav beprovided for), when the parts shown in Fig. 3 begin to move back to theposition shown in Fig. 1, which position they reach at the end of thefourteenth stitch. During this operation, the thread holder 28 pushesout the end a0 of the needle thread from under the part 37 of the springarm 36, and the pointed ends of the knives 26 and 27 engage with theneedle and shuttle threads, respectively, and as the machine stops theinertia of the parts gives a quick motion to the rod 42, which carries arack engaging with the gear wheel 29. This motion is in the direction ofthe arrow shown in Fig. 1, and severs the needle and shuttle threads inthe usual way.

After the threads have been severed, a spring, operating in the usualmanner, restores the parts to their initial position, as shown inFig. 1. During this cutting operation, as the parts are thrown in acounterclockwise direction from the position shown in Fig. 1, the heel28* of the thread holder 28 passes from under the end 37 of the springarm 36, and as the parts are retracted, under the influence of theaforesaid spring (not shown), the heel 28 of the thread holder, strikingagainst the right hand part 38 of the end of the spring arm 36, has atendency to throw this arm down, so as to cause it to come into the pathof the rear end of the knife 27, but this actionis prevented by thecurved guard 31, which limits the forward motion of the end of thespring 36.

I claim 1. In a thread severing and holding means, the combination witha throat plate, of movable'means for severing the needle thread, aplurality of clamping parts, including a stationary part, for holdingthe severed end of the needle thread between them, a member having athread carrying portion operating between said clamping parts forcarrying the severed end of said thread between said parts, saidclamping parts being located beneath the upper surface of the throatplate.

2. In a thread severing and holding means, the combination of a movablemeans for severing the thread, with a plurality of clamping membersincluding a stationary member for holding'a severed end, and a movablemeans attached to said severing means for bringing said severed endbetween said clamping members, said movable means also acting to ejectsaid-severed end from between said clamping members.

In testimony whereof, I aflix my signature, in presence of twowitnesses.

JOHN W. DARLEY, JR. Witnesses:

N. CURTIS LAMMQND, A. W.-NEALE, Jr.

